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#1
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WIMPs AWOL Yet Again
One hopes Dan Hooper will turn down the hype now.
http://journals.aps.org/prl/abstract...ett.116.051102 [[Mod. note -- The preprint version of this appears to be http://arxiv.org/abs/1506.05104 -- jt]] Gamma-ray excess in MWG central region is NOT due to WIMPs, or any other form of ad hoc hypothetical particle dark matter. Rather it is due to stellar-mass astrophysical sources at the 10 sigma level. The sources remain to be fully identified, but millisecond pulsars are considered to be the most likely candidates. Might they actually be a completely unexpected population of stellar-mass black holes? We shall see! RLO http://www3.amherst.edu/~rloldershaw "Those who expect the old ideas to last forever are doomed to live confined within them" |
#2
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WIMPs AWOL Yet Again
In article ,
"Robert L. Oldershaw" writes: Gamma-ray excess in MWG central region is NOT due to WIMPs, or any other form of ad hoc hypothetical particle dark matter. Even assuming that this is true, Rather it is due to stellar-mass astrophysical sources at the 10 sigma level. Can you explain this? The sources remain to be fully identified, but millisecond pulsars are considered to be the most likely candidates. OK. Might they actually be a completely unexpected population of stellar-mass black holes? We shall see! Can you explain how stellar-mass black holes could emit the radiation in question---quantitatively? I remind posters here that you still cannot explain why this putative population is not seen in microlensing searches. |
#3
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WIMPs AWOL Yet Again
On Sunday, February 7, 2016 at 12:44:54 PM UTC-5, Phillip Helbig
(undress to reply) wrote: =20 I remind posters here that you still cannot explain why this putative=20 population is not seen in microlensing searches. If the population of objects emitting this radiation turns out to be on the order of 100,000 millisecond pulsars, as proposed by the authors of the paper, then microlensing studies should detect them if they are looking in the right place and microlensing observations are feasible and effective in this particular setting. [[Mod. note -- Alas, microlensing observations aren't feasable and effective in this setting: * It would be hard to distinguish brightness fluctuations caused by microlensing from those caused by turbulence in the interstellar medium. * Microlensing only happens if the lens is *very* precisely lined up along the line of sight to the background object. Using the central bulge of our galaxy (= on the order of 1e10 stars = on the order of 1e10 potential lenses) gives a probability of any given source being microlensed at any given time is on the order of 1e-7 or so, which is just detectable by monitoring star fields of 10s to 100s of millions of background stars. So a population of "only" 1e5 millisecond pulsars is going to produce something on the order of 1e5 times fewer microlensing events, i.e., in practice we probably wouldn't see any events. -- jt]] |
#4
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WIMPs AWOL Yet Again
On Monday, February 8, 2016 at 9:03:15 PM UTC-5, Robert L. Oldershaw wrote:
And here is another negative result in the endless "WIMP" search. http://arxiv.org/abs/1603.05120 The authors say it confirms the latest LUX and SuperCDMS no-show results. RLO (yawn) http://www3.amherst.edu/~rloldershaw |
#5
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WIMPs AWOL Yet Again
On Friday, March 18, 2016 at 4:57:34 AM UTC-4, Robert L. Oldershaw wrote:
On Monday, February 8, 2016 at 9:03:15 PM UTC-5, Robert L. Oldershaw wrote: And here is another negative result in the endless "WIMP" search. And here is yet another: http://arxiv.org/abs/1603.08914 This time it from CMS at LHC. |
#6
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WIMPs AWOL Yet Again
On Thursday, March 31, 2016 at 2:27:52 AM UTC-4, Robert L. Oldershaw wrote:
On Friday, March 18, 2016 at 4:57:34 AM UTC-4, Robert L. Oldershaw wrote: On Monday, February 8, 2016 at 9:03:15 PM UTC-5, Robert L. Oldershaw wrote: And here is another negative result in the endless "WIMP" search. And here is yet another: http://arxiv.org/abs/1603.08914 This time it from CMS at LHC. Following on the heels of the "WIMP" no-show in the LUX experiment, we now have yet another "WIMP" no-show at PandaX-II. http://arxiv.org/abs/1607.07400 RLO http://www3.amherst.edu/~rloldershaw |
#7
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WIMPs AWOL Yet Again
In article ,
"Robert L. Oldershaw" writes: And here is another negative result in the endless "WIMP" search. And here is yet another: http://arxiv.org/abs/1603.08914 This time it from CMS at LHC. Following on the heels of the "WIMP" no-show in the LUX experiment, we now have yet another "WIMP" no-show at PandaX-II. http://arxiv.org/abs/1607.07400 Why the scare quotes? One could have said the same things about gravitational waves for several decades. Would that have prove that they don't exist? No. |
#8
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WIMPs AWOL Yet Again
On Wednesday, July 27, 2016 at 6:54:01 PM UTC-4, Phillip Helbig (undress to reply) wrote:
Why the scare quotes? One could have said the same things about gravitational waves for several decades. Would that have prove that they don't exist? No. ----------------------------- When a "WIMP" is actually discovered, and not rejected as another in a long, long line of false-positives, then I will remove the reality quotes. RLO http://www3.amherst.edu/~rloldershaw |
#9
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WIMPs AWOL Yet Again
On Friday, July 29, 2016 at 12:10:58 AM UTC-4, Robert L. Oldershaw wrote:
When a "WIMP" is actually discovered, and not rejected as another in a long, long line of false-positives, then I will remove the reality quotes. Today (7/28/16) we have a report from the H.E.S.S Collaboration. They have been observing the center 300 pc of the Galaxy for 10 years looking for evidence for gamma-rays attributable to "particle dark matter annihilations". http://arxiv.org/abs/1607.08142 Results after 10 years of data: no-show. RLO http://www3.amherst.edu/~rloldershaw |
#10
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WIMPs AWOL Yet Again
In article ,
"Robert L. Oldershaw" writes: When a "WIMP" is actually discovered, and not rejected as another in a long, long line of false-positives, then I will remove the reality quotes. I expect you to put them around "primordial black holes" as well until these are discovered. Today (7/28/16) we have a report from the H.E.S.S Collaboration. They have been observing the center 300 pc of the Galaxy for 10 years looking for evidence for gamma-rays attributable to "particle dark matter annihilations". http://arxiv.org/abs/1607.08142 Results after 10 years of data: no-show. No problem. If they hadn't looked, they wouldn't have been able to draw any conclusions. Observations are the basis of science. Note also that one of the main motivation for the MACHO and similar collaborations was to find a substantial fraction of the dark matter in compact objects in our galactic halo. After 25 years of data, no show. Gravitational waves were a no show for 100 years. |
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